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[Federal Register Volume 77, Number 77 (Friday, April 20, 2012)]
[Proposed Rules]
[Pages 23637-23638]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-9545]

========================================================================
Proposed Rules
                                                Federal Register
________________________________________________________________________

This section of the FEDERAL REGISTER contains notices to the public of 
the proposed issuance of rules and regulations. The purpose of these 
notices is to give interested persons an opportunity to participate in 
the rule making prior to the adoption of the final rules.

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Federal Register / Vol. 77, No. 77 / Friday, April 20, 2012 / 
Proposed Rules

[[Page 23637]]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-0228; Directorate Identifier 2012-NE-09-AD]
RIN 2120-AA64

Airworthiness Directives; Pratt & Whitney Division Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain Pratt & Whitney Division PW4000-94'' and PW4000-100'' turbofan 
engines having a 1st stage high-pressure turbine (HPT) seal support, 
part number (P/N) 55K601 or P/N 50K532, installed. This proposed AD was 
prompted by 58 reports of cracked 1st stage HPT air seal rings, 
including 15 in-flight engine shutdowns. This proposed AD would require 
installation of a redesigned 1st stage HPT seal support that was 
introduced to the PW4000 engine fleet through service bulletins issued 
in the year 2000. We are proposing this AD to prevent failure of the 
1st stage HPT air seal ring, which could lead to an internal oil fire, 
uncontained engine failure, and damage to the airplane.

DATES: We must receive comments on this proposed AD by June 19, 2012.

ADDRESSES: You may send comments, using the procedures found in 14 CFR 
11.43 and 11.45, by any of the following methods:
     Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
     Fax: 202-493-2251.
     Mail: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590.
     Hand Delivery: Deliver to Mail address above between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Pratt & Whitney, 400 Main St., East Hartford, CT 06108; phone: 860-565-
8770; fax: 860-565-4503. You may review copies of the referenced 
service information at the FAA, Engine & Propeller Directorate, 12 New 
England Executive Park, Burlington, MA. For information on the 
availability of this material at the FAA, call 781-238-7125.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The AD docket contains this proposed AD, the regulatory 
evaluation, any comments received, and other information. The street 
address for the Docket Office (phone: 800-647-5527) is in the ADDRESSES 
section. Comments will be available in the AD docket shortly after 
receipt.

FOR FURTHER INFORMATION CONTACT: James Gray, Aerospace Engineer, Engine 
& Propeller Directorate, FAA, 12 New England Executive Park, 
Burlington, MA 01803; phone: 781-238-7742; fax: 781-238-7199; email: 
james.e.gray@faa.gov.

SUPPLEMENTARY INFORMATION:

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2012-0228; 
Directorate Identifier 2012-NE-09-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD because of those comments.
    We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We 
will also post a report summarizing each substantive verbal contact we 
receive about this proposed AD.

Discussion

    We received 58 reports of cracked 1st stage HPT air seal rings, 
including 15 in-flight engine shutdowns, in certain PW4000-94'' and 
PW4000-100'' turbofan engines. Pratt & Whitney's investigation has 
revealed that vibratory excitation causes the 1st stage HPT air seal 
ring to crack when a 1st stage HPT seal support, P/N 55K601 or P/N 
50K532, is installed. Installing the redesigned 1st stage HPT seal 
support, P/N 50K153, that was introduced to the PW4000 engine fleet for 
another reason through service bulletins issued in the year 2000 also 
prevents cracking of the 1st stage HPT air seal ring. Cracking of the 
1st stage HPT air seal ring, if not corrected, could result in failure 
of the 1st stage HPT air seal ring, which could lead to an internal oil 
fire, uncontained engine failure, and damage to the airplane.

Relevant Service Information

    We reviewed Pratt & Whitney Service Bulletin (SB) No. PW4ENG 72-
721, Revision 2, dated November 30, 2011, and SB No. PW4G-100-72-166, 
Revision 2, dated December 2, 2011. The service information describes 
procedures for replacing the 1st stage HPT seal support, P/N 55K601, or 
P/N 50K532, with a redesigned 1st stage HPT seal support, P/N 50K153.

FAA's Determination

    We are proposing this AD because we evaluated all the relevant 
information and determined the unsafe condition described previously is 
likely to exist or develop in other products of the same type design.

Proposed AD Requirements

    This proposed AD would require accomplishing the actions specified 
in the service information described previously. This proposed AD would 
also require fluorescent-penetrant-inspection or eddy current-
inspection of the 1st stage HPT air seal ring for cracks, and replacing 
it if found cracked.

Costs of Compliance

    We estimate that this proposed AD would affect 446 Pratt & Whitney 
Division PW4000-94'' and PW4000-100'' turbofan engines installed on 
airplanes of U.S. registry. We also estimate that it would take about 3 
work-hours to perform the actions

[[Page 23638]]

required by this AD. The average labor rate is $85 per work-hour. 
Required parts would cost about $45,723 per engine. Based on these 
figures, we estimate the total cost of the AD to U.S. operators to be 
$20,506,188.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD would not 
have a substantial direct effect on the States, on the relationship 
between the national Government and the States, or on the distribution 
of power and responsibilities among the various levels of government.
    For the reasons discussed above, I certify this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, February 26, 1979),
    (3) Will not affect intrastate aviation in Alaska, and
    (4) Will not have a significant economic impact, positive or 
negative, on a substantial number of small entities under the criteria 
of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec.  39.13  [Amended]

    2. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

Pratt & Whitney Division: Docket No. FAA-2012-0228; Directorate 
Identifier 2012-NE-09-AD.

(a) Comments Due Date

    We must receive comments by June 19, 2012.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to the following Pratt & Whitney Division 
turbofan engines:
    (1) PW4000-94'' engine models PW4050, PW4052, PW4056, PW4152, 
PW4156, PW4650, PW4060, PW4060A, PW4060C, PW4062, PW4062A, PW4156A, 
PW4158, PW4160, PW4460, and PW4462, including models with any dash-
number suffix, with a 1st stage high-pressure turbine (HPT) seal 
support part number (P/N) 55K601 or P/N 50K532, installed.
    (2) PW4000-100'' engine models PW4164, PW4164C, PW4164C/B, 
PW4168, and PW4168A with a 1st stage HPT seal support P/N 55K601 or 
P/N 50K532, installed.

(d) Unsafe Condition

    This AD was prompted by 58 reports of cracked 1st stage HPT air 
seal rings, including 15 in-flight engine shutdowns. We are issuing 
this AD to prevent failure of the 1st stage HPT air seal ring, which 
could lead to an internal oil fire, uncontained engine failure, and 
damage to the airplane.

(e) Compliance

    Comply with this AD the next time that the engine is separated 
at the M-flange and the HPT module is removed from the engine.
    (1) Remove the 1st stage HPT seal support, P/N 55K601 or P/N 
50K532, from service and replace it with a 1st stage HPT seal 
support, P/N 50K153.
    (2) Remove the 1st stage HPT air seal ring from the engine and 
fluorescent-penetrant-inspect, or eddy current-inspect, it for 
cracks. If found cracked, remove the 1st stage HPT air seal ring 
from service.

(f) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, may approve AMOCs for 
this AD. Use the procedures found in 14 CFR 39.19 to make your 
request.

(g) Related Information

    (1) For more information about this AD, contact James Gray, 
Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New 
England Executive Park, Burlington, MA 01803; phone: 781-238-7742; 
fax: 781-238-7199; email: james.e.gray@faa.gov.
    (2) Pratt & Whitney Service Bulletin (SB) No. PW4ENG 72-721, 
Revision 2, dated November 30, 2011, and SB No. PW4G-100-72-166, 
Revision 2, dated December 2, 2011, pertain to the subject of this 
AD.
    (3) For service information identified in this AD, contact Pratt 
& Whitney, 400 Main St., East Hartford, CT 06108; phone: 860-565-
8770; fax: 860-565-4503.
    (4) You may review copies of the service information at the FAA, 
New England Region, 12 New England Executive Park, Burlington, MA. 
For information on the availability of this material at the FAA, 
call 781-238-7125.

    Issued in Burlington, Massachusetts, on April 16, 2012.
Peter A. White,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2012-9545 Filed 4-19-12; 8:45 am]
BILLING CODE 4910-13-P
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